A new decks edition comes out every 3 years. Yes, there's a 2001 edition, and the next one is supossed to come in 2004, so if you're not in a hurry, you might as well wait for it.
I don't exactly remember why is it, but every new edition is related with the ADA doing something on the boards. Do a search on the dental forum, this is where I read this info, actually I remembered Yah-e was the poster.
For part 1, I had the 98 version and my friend had the 2001, so I got to compare them. The major difference I've seen between editions is mainly format related. I mean, the newer ones will have more graphics, tables, will be more concise, etc. It's like they'll put the same text format information, but in a more study friendly format, like easier to read, in tables, easier to memorize, you know stuff like that.
I personally will have liked to use the 2001 edition better, 'cause I'm defitnely a graphics and tables person, I totally need to see information compared agaisnt each other in a table, in order to be able to get started learning something new. As matter of fact, that's my main study technique. And since I've been out of school for a while now, all this basic subjects were almost new to me.
Anyhow, just go to
www.dentaldecks.com, I guess they should have something about that posted. Write them and ask them if they're going to be releasing a new version. 'cause the ADA is supossed to begin to do some changes in the boards, maybe this could affect the dental decks, I dunno.
Hope this helps...